Geogrpahy aqa rivers

Abrasion

The pebbles being transported wear away the bed and the banks of the river channel

Attrition

Erosion caused when rocks and boulders transported by waves bump into each other and break int smaller pieces

Alluvium

Rock particles (clay, silt, sand or gravel) deposited by a river

Bedload

The material (rocks etc) carried by a river by being bounced or rolled along its bed

Confluence

The point at which the river meets the sea

Cross profile

What the river channel looks like at any point- how the width and depth change

Deposition

Where a river has low energy/velocity and the bedload/sediment is dropped off

depth

How deep a river is - increases downstream, a result of being joined by a number of tributaries

Discharge

The amount of water in the river passing a specific point at a given time. This becomes larger downstream as a result of the joining of many tributaries

Drainage basin

The area of land that is drained by a river and its tributaries

Erosion

The wearing away of the bed and the banks of the river channel by abrasion, hydraulic action, solution and attrition

Estuary

The tidal mouth of a river, with large, flat expenses of mud exposed at low tide

Flood plain

The wide, flat floor of a river valley- the land on either side of the river made of sediments (alluvium) deposited by the river

Flooding

When the discharge of the river reaches the channels capacity and the river overflows and busts it banks spreading water into the flood plain

Hard engineering

Managing a river by building man made structures such as dams

Hydraulic power

The sheer force of the water by itself can erode material from the bed and the banks of the river channel

Hydrograph

A graph showing the discharge/volume of water in the river overtime after a flood event

Gorge

A steep sided, narrow rocky valley where a waterfall has retreated

Gradient